All I'm asking is for a simple answer and not a diatribe on how to archivally process a print. Once again, how long must a print life be to be considered archival? The answer is as simple as "X years". I don't belive there is an answer to that question which isn't accompanied by a huge amounts of caveats, ifs and buts. i.e. Its imposibble to define with any accuracy so its a meaningless term to say a print is archival. You can only say you have done such and such archval processing and archival framing but you can't say how long a print will survive.
Rob C is quite correct, there is no acceptable industry standards, Over the past 50 years I have seen numbers that someone seemed to have pulled out of thin air, when questioned could not provide the source, 75 years, 300 years, even 500 years. I recall that Fred Pickering wrote in one of his newsletters that an archival print should last 300 years, no reference as to how make that determination. I have seen different numbers for RC vs FB, when I last asked Ilford about RC vs FB Ilford, at the time, had taken the position that a well processed RC print will last as long a FB print.
What is the best method to achieve this standard, Kodak and Ilford do not agree, and the methods have changed over time, in the 60s it was recommended to use hypo eliminator, not so much in today's world. So if look at my prints that I made in the 60s and early 70 when I used hypo eliminator can I still call them archival? The only prints that I have that have not held up over the past 50 years are ones that were printed on GAF RC, on the other hand prints made on Kodak RC paper have held up as well any of my FB prints.
10 years or longer someone posted a proposal to set up a quality control company, like Good House Keeping who would certify prints as being archival,
needless to say that there was quite a bit of blowback.
If asked by a buyer about my work being "Archival" I tell them that I process for permanency using current methods, but as far I know there are no universal standards so I don't really know, and as I will long dead cant give a guarantee.